1. Field of the Invention
The present invention relates to a new and improved graphic arts apparatus for exposing copy sheets to light flowing from a controlled light source through an image sheet pressed against a transparent panel of a glass frame. The graphic arts apparatus is especially designed for ease in operation so that high production rates can be achieved with high quality reproduction. A novel glass frame and glass frame supporting yoke is provided for facilitating, cleaning and/or replacement of transparent panels of glass or plastic when the need arises.
2. Description of the Prior Art
One of the problems associated with exposure devices is the problem caused by dust and other particles often present on image sheets, copy sheets and rigid transparent sheet materials used in such exposure devices. Such accumulations of dust and other particles cause "pinholes" to be present in a printed copy and for this reason, diffused light rather than collimated light is often desired to minimize the presence of such pin-holes. It is also sometimes desirable to provide a sheet of light-modifying media spaced between the source of light and a positive or negative image sheet and a light sensitive copy sheet which are contained between a rigid, transparent sheet of glass or plastic material and a vacuum blanket for holding the sheets in precise registration.